Electrical connecter



Aug. 10, 1937- A. E. ANDERSON 2,089,844

ELECTRICAL CONNECTER Filed March 28, 1934 ZS INVENTOR.

BY ywwewcw ATTORNEY.

Patented Aug. 10, 1937 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to an electrical connecter and more particularly to an electrical connecter of the plug and receptacle type.

The object of the invention is to provide a novel and improved electrical connecter for multi-polar electrical systems, and in which provision is made for insuring that the correct polarity is produced and maintained when the electrical connection is made.

A further and more specific object of the invention is to provide a plug or a socket member, and preferably both such members, for use in multi-polar electrical systems, which are so constructed as to prevent reversal of polarity, particularly by insuring that the proper contact member is fitted into the proper recess in its insulating mounting, during the assembly of the contacts in the plug or socket member.

Another object of the invention is to provide a novel and improved electrical connecter of the character specified in which the reversal of polarity is prevented and which may be manufactured at minimum expense.

With these objects'in view and such others as 5 may hereinafter appear, the invention consists in the electrical connecter and particularly in the plug and receptacle electrical connecter and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawing illustrating the preferred embodiment of the invention, Fig. 1 is a vertical longitudinal section through an electrical connecter of the plug and receptacle type embodying the present invention; Fig. 2 is a cross-sectional View on the line 2-2 of Fig. 1; Fig. 3- is a sectional view on the line 3-3 of Fig. 1; Figs. 4, 5, 6 and 7 are each details in longitudinal side and end elevation of the different male contact members embodied in the electrical connecter shown in Figs. 1 and 2. Fig. 4a is an end elevation of the male contact members shown in Figs. 4, 5, 6, and '7 looking toward the right.

Fig. 4b, Fig 5%, Fig. 6a., and Fig. 7a are end elevations of the male contact members shown in Figs 4, 5, 6, and '7, looking toward the left.

In general, the invention contemplates a novel and improved construction of electrical connecter, and particularly of an electrical connecter of the plug and socket type adapted for use in a multi-pole electrical system such as a two, three or four-wire system, which is so constructed as to insure against the reversal of polarity when the electrical connection is made, and at the same time to enable an efficient and desirable character of connection to be made. Accordingly, the invention contemplates a construction in which a plurality of contact members, either male or female, are so constructed as to T be incapable of being fitted into their insulating mounting in either the plug or receptacle, except in a predetermined relation to one another, so as to thereby insure the maintenance of the proper polarity between the different contact members. In the preferred embodiment of the invention the contact members are made from bar stock of different shapes in cross-section and are provided with portions of the original cross-sectional shape of the bar, and such por- 15 tions are arranged to be received within holes in the insulating mounting within the plug or receptacle, and said portions of the contact members are arranged to correspond only with the particular hole in which it is designed to be in- Q serted so that when the individual contacts are assembled in the mounting, the proper contact must be placed within the proper hole in the mounting in order that the assembly may be. made. After assembly, in order to insure the 2'25 introduction of the plug member into the socket member in predetermined definite relation, both plug and receptacle are provided with cooperat ing members for effecting this result, and with this construction it is possible to constructthe 30 male contact members so that the portions thereof which fit into the female contact members may be of circular section, thus insuring most eificient electrical connection between these parts.

Referring now to the drawing which illustrates the preferred embodiment of the invention, It] represents the plug member and 12 the socket member of the improved electrical connecter. The plug member ll] of the electrical connecter is provided with a metal casing I4 herein shown as 40 cylindrical in shape and arranged to telescope. within the projecting portion of a casing l6 of the socket member, as illustrated in Fig. 1. The casings l4, l6 of the plug and socket members are respectively provided with a recess and a pro- 45 jecting lip I8, 20 which must be brought into alignment in order to permit the casings l4, [6 to telescope one within the other, as will be ap parent from an inspection of Figs. 1 and 3, thus causing the casings to assume predetermined re- '5 lationship when the electrical connection is to be made.

The casings I4, l6 have mounted therein insulating members 22, 24 provided with holes extended therethrough and within which the male. and 55 female contact members 26, 28 of the plug and socket, respectively, are mounted. In accordance with the present invention the individual contact members 26, 28 of the plug and socket, respectively, are made of bar stock and each contact is preferably made of bar stock of a diiferent cross-sectional shape or of a different size and at least one portion 29 of each contact, either male or female, is of the shape and size in section of the original bar from which the contact is made.

The holes extended through the insulating members 22, 24 are provided with non-cylindrical rear portions 30 for the reception of the non cylindrical portions 29 which co-operate to pre Vent rotation of the contact members in the holes into which the contact members are inserted from the rear side of the insulating members The holes in the insulating members are provided at their front ends with relatively small portions which form shoulders E2 within the insulator.

The shoulders 42 permit the non-cylindrical rear portion 30 of the hole to extend from the shoulder to the rear face of the insulator in that member of the connecter which is alive when the members of the connection are disconnected. The live member of the connection is usually the socket member, but in some cases it is desirable to have the plug member the live mem-' her, and therefore the insulating members 22,

24 are both provided with the shoulders 42. The

non-cylindrical rear portion of the holes in the insulatingmembers; may extend but a short distance intoth einsulating member from the In Fig. 2, four contact members are repre sented, and three'of these are provided with relatively narrow non-cylindrical rear portions marked 29, which enter the shallow or narrow non-cylindrical portions 38 of three of the holes in the insulating members 22, 2 5. These three contact members are shown separately in Figs. 5, 6 and 7, andare the active or current-carrying contact members. when the plug and socket members are connected together in the operative position or relation. The fourth contactmember shown in Fig. 2, is shown separately in Fig. l and serves to illustrate the contact members when provided with longer non-cylindrical rear portions, and by reference to Fig. 4, it willbe seen that the non-cylindrical portion of the contact members may be of bar stock, and when so made the amount of machine work required to produce the contact membersmay be materially reduced and the cost correspondingly lessened.

In producing the male contact members from bar stock, it is preferred to turn the frontend portions 26 into cylindrical form for introduction into the cylindrical socket 38 of the female contact members 28 in order'to' provide a most satisfactory electrical connection.

-When the male contact member are provided with a narrow non-cylindrical rear portion as illustrated in Figs. 1, 5, 6 and 7, the portion inber should be grounded while such leak occurs,

a path for the current is provided to the ground 'by'means of the normally inactive ground contact-members 29 shown in Figs. 1 and 4, inasmuch as the male contact member 29 shown in I Fig. 4, is provided in the non-cylindrical rear portion with the socket 33 into which is extended the boss 3'! on a metal ring 35, which contacts with the metal casing Ill and is clamped thereto by the hollow member or shell 36, which is in threaded engagement with the casing ID. The metal ring 35 may be designated the grounding ring, and it is provided with a hole it which is extended into the boss 3i and in which a grounding wire (not shown) is soldered in a manher well understood. 7

Between the grounding ring 35 and the rear face of the insulating member of the plug and socket members, is located a disk or member 46 which serves to retain the contact members in their insulating members and prevents said contact members from. being moved out of the holes in the insulating members, either by a pull upon the wires soldered to said contact members or by gravity when the plug or socket members are held or placed in an upright position with their front ends uppermost.

It is preferred to make thecontact members slightly smaller than the holes in which they are located, as indicated by the heavy black line in Fig. 1, so that they may be readily inserted and removed from said holes and also so that they may be moved laterallywith relation to the length of said holes, whereby the contact members may be self-centering when the plug member is coupledwith the socket member.

' By reference to Fig. 2, it will be seen that the four contact members are readily distinguishable from one another by means of the diiferent shapes of the non-cylindrical rear portions, and this feature facilitates ready renewal of 7 contact members when burned off in service, in that the burnt-01f contact or contacts may be ordered from the manufacture-r'by the shape of its noncylindricalrear portion, and avoids return of the plug or socket member to the manufacturer, because the renewal of the contact member can be effected by unskilled labor as it only requires dropping the new contact member into its appropriate hole the insulating member from which the burnt-off contact member is removed. The shoulder 42 within the insulating member at the front end thereof serves as a stop to limit the movement of the contact memberwithin the insulating member when the contact member is inserted ordropped into the hole in the insulating member. So also the shoulder of the socket member, which is usually the live member of ting his fingers in contact with the front end of duce the danger of the operator or workman getthe socket contact member, and thereby avoids liability of serious accidents to the operator.

While the preferred embodiment of the invention has been herein illustrated and described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is:

1. In an electrical connection, in combination, two metallic casings provided with means for permitting them to be operatively engaged in only one position, an insulating member within each casing secured in predetermined relation thereto, each of said insulating members having a plurality of holes extended through them and provided with non-cylindrical rear portions of different areas and shapes in cross-section and with front portions of smaller areas forming positioning and protective shoulders with the portions of larger areas, a plurality of contact members insertible into the holes in each insulating member from the rear side thereof and provided with non-cylindrical rear portions to fit into the non-cylindrical portions of said holes and prevent rotation of said contact members in said insulating members, and retaining members for said contact members co-operating with said contact members to prevent longitudinal movement of the contact members out of said holes and provided with openings of smaller area in line with the non-cylindrical rear portions of said contact members, said contact members being engaged when said casings are engaged. 2. In a plug member of an electrical connection, in combination, an insulating member having a hole extended through it and provided with a front portion and a non-cylindrical rear portion of larger area in cross section than said front portion, and a contact member insertible into said hole from the rear side of said insulating member to place it in its operative position in the insulating member and having a cylindrical front portion and a non-cylindrical rear portion of larger area in cross-section than said cylindrical front portion, said non-cylindrical rear portion being of substantially the same shape and size in cross-section as the non-cylindrical portion of the said hole to fit loosely in the noncylindrical portion of said hole and prevent rotation of said contact member while permitting bodily movement of the latter in its operative position in the direction of the length of said hole, said cylindrical front portion being extended through and beyond the front portion of said hole, and means for retaining said contact member in said hole.

3. In an electrical connection, in combination, an insulating member having a plurality of holes extending through it and each provided with a front portion and a non-cylindrical rear portion of larger area in cross section than said front portion, said rear portions being of different sectional shapes, and a plurality of contact members insertable into said holes from the rear side of said insulating member to place them in their operative positions in the insulating memher and each having a cylindrical front portion and a non-cylindrical rear portion of larger area in cross section than said cylindrical front portion, said non-cylindrical rear portions being of substantially the same sectional shape and size in cross section as the corresponding non-cylindrical portions of the said holes to fit loosely in the non-cylindrical portions of the said holes and prevent rotation of said contact members while permitting bodily movement of the latter in their operative positions in the direction of the length of said holes, said cylindrical front portions being extended through and beyond the front portions of said holes, and means for retaining said contact members in said holes.

4. In an electrical connection, in combination, an insulating member having a plurality of holes extending through it and each provided with a front portion and a non-cylindrical rear portion of larger area in cross section than said front portion, said rear portions being of different sectional shapes, a plurality of contact members insertable into said holes from the rear side of said insulating member to place them in their operative positions in the insulating member and each having a cylindrical front portion and a non-cylindrical rear portion of larger area in cross section than said cylindrical front portion, said non-cylindrical rear portions being of substantially the same sectional shape and size in cross section as the corresponding non-cylindrical portions of the said holes, and means for retaining said contact members in said holes.

ALF E. ANDERSON. 

